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Orthostatic hypotension (also known as
postural hypotension,[1],
orthostasis, and, colloquially, as head rush or a
dizzy spell and to some people "the elevator
effect") is a form of hypotension in which a person's blood pressure
suddenly falls when the person stands up. The decrease is typically
greater than 20/10 mm Hg,[2]
and may be most pronounced after resting.

Symptoms

Symptoms, which generally occur after sudden standing or
stretching (after standing), include dizziness, euphoria, bodily dissociation,
distortions in hearing, lightheadedness, headache, blurred or dimmed vision (possibly to the point of
momentary blindness),
generalized (or extremity) numbness/tingling and fainting, coat hanger pain
(pain centered in the neck and shoulders), and in rare, extreme
cases, vasovagal syncope. They are consequences of
insufficient blood
pressure and cerebralperfusion (blood
supply). Occasionally, there may be a feeling of warmth in the head
and shoulders for a few seconds after the dizziness subsides.

Diagnosis

A simple test for OH measures the person's blood pressure while
seated or reclining at rest, and again upon standing up. A sudden, significant fall in
blood pressure upon standing indicates orthostatic hypotension.
Blood pressure may drop immediately upon standing, or any time
during the first couple of minutes after standing. In addition, the
heart rate should also be measured for both positions. A
significant increase from supine to standing may indicate a
compensatory effort by the heart to maintain cardiac output.

Causes

Orthostatic hypotension is primarily caused by gravity-induced
blood pooling in the lower extremities, which in turn compromises
venous return, resulting in decreased cardiac output and subsequently lowering
of arterial pressure. For example, if a person changes from a lying
position to standing, he or she will lose about 700 ml of blood from the thorax. It can also be noted that
there is a decreased systolic
(contracting) blood pressure and a decreased diastolic (resting) blood pressure.[4] The
overall effect is an insufficient blood perfusion in the upper part
of the body.

Still, the blood pressure does not normally fall very much,
because it immediately triggers a vasoconstriction (baroreceptor reflex), pressing the blood up
into the body again. Therefore, a secondary factor that causes a
greater than normal fall in blood pressure is often required. Such
factors include hypovolemia, diseases, medications, or, very
rarely, safety harnesses.[5]

Another disease is called Dopamine beta
hydroxylase deficiency, that is thought to be underdiagnosed
also, that causes loss of sympathetic noradrenergic function and is
characterized by a low or extremely low levels of norepinephrine
but an excess of dopamine.[6]

It is a symptom that quadriplegics and paraplegics might
experience due to multiple systems' inability to maintain a normal
blood pressure and blood flow to the upper part of the body.

Medication

Orthostatic hypotension can be a side effect of certain anti-depressants, such as tricyclics[8]
or MAOIs.[9].
[10]
Orthostatic hypotension can also be a side effect of
alpha1 adrenergic blocking agents. Alpha1
blockers inhibit vasoconstriction normally initiated by the baroreceptor reflex upon postural change
and the subsequent drop in pressure.[11]

Harnesses

The use of a safety harness can also contribute to orthostatic
hypotension in the event of a fall. While a harness may safely
rescue its user from a fall, the leg loops of a standard safety or
climbing harness further restrict return blood flow from the legs
to the heart, contributing to the decrease in blood pressure.

Other risk
factors

Patients who are prone to orthostatic hypotension are the
elderly, postpartum mothers, those who have been on
bedrest and teenagers because of their large amounts of growth in a
short period of time. People suffering from anorexia
nervosa and bulimia nervosa often suffer from
orthostatic hypotension and it is a common side effect of these
mental illnesses. Certain recreational drugs such as cannibis or
opioids may cause a head rush. Consuming alcohol may also lead to
orthostatic hypotension due to its dehydrating effects on the
body.

Treatment and management

There are medications to treat hypotension. In addition there
are several lifestyle issues, which however are most often specific
to a certain cause of orthostatic hypotension.

Lifestyle
advice

Standing slowly rather than quickly, as the delay can give the
blood vessels more time to constrict properly. This can help avoid
incidents of syncope (fainting).

Take a deep breath and flex your abdominal muscles while rising
to maintain blood and oxygen in the brain. This, however, may be
contraindicated in individuals with Stage 2 hypertension. Usually medical
personnel have their patients "dangle" before rising from bed to
decrease the likelihood of dizziness/falling due to orthostatic
hypotension. The dangling is done by having the patient sit on the
side of their bed for about a minute so they do not have the sudden
dizziness.

Maintaining an elevated salt intake, through sodium supplements
or electrolyte-enriched drinks. A suggested value is 10 g per day;
overuse can lead to hypertension and should be avoided.

Maintaining a proper fluid intake to prevent the effects of
dehydration.

As eating lowers blood pressure, take your food in a larger
number of smaller meals. Take extra care when standing after
eating.

When orthostatic hypotension is caused by hypovolemia due to
medications, the disorder may be reversed by adjusting the dosage
or by discontinuing the medication.

When the condition is caused by prolonged bed rest, improvement
may occur by sitting up with increasing frequency each day. In some
cases, physical counterpressure such as elastic hose (stockings) or whole-body inflatable suits
may be required.

Many people who experience orthostatic hypotension are able to
recognise the symptoms and quickly adopt a "squat position" to
avoid falling during an episode. This is because they are usually
unable to co-ordinate a return to sitting in a chair, once the
episode has commenced.

Avoiding bodily positions that impede blood flow, such as
sitting with knees up to chest or crossing legs.

Prognosis

The prognosis for individuals with orthostatic hypotension
depends on the underlying cause of the condition.